Make sure it's not skunks. I have a real problem with them here in the mountains, but I know you guys have them over near the coast too.
I have to let my chickens out at 8am+ to avoid the little bastards, since they will fit through very small gaps and will take the smaller ones away. I thought it was a falcon taking my babies until I caught one in the act. No matter how much I fill in the holes, they get back in; putting the birds in before dusk and much after dawn solves it well enough, though.
I didn't see if you said you fixed the open areas on top, but the FIRST thing I thought was that if the chickens can fly in, ANYTHING can climb in. I wouldn't leave any open areas at all, especially because you now know you have a predator. Just killing this one is NOT going to stop the next one from getting in. Go for it, I would (nasty jerks, nothing would get away with killing my babies if I have anything to say about it!), but then take every PRECAUTIONARY measure you can and don't allow it to happen again. Traps and poison are fine, but you need to bar access to the coop in the first place. If that means you have to go out and round them up each night, so be it. If you want them to be safe, you'll do what it takes! Good luck with the nasty bugger, I hope you get him!
Fiance shot *something* last night.....or so he says......says "IT" is coming up from underneath the barn & sneaking in the chicken door into the barn. I removed my chicks and put them somewhere very safe. I'm not losing anymore....and that's a fact!!!! Well, anyway, he was sitting outside waiting...said he saw eyes x3 and on 3rd time he shot. Now, I wouldn't tell him this......but.....I didn't see any blood or fur or NOTHING........but he's SURE he got "IT". Says there's no way he didn't shoot it's face off. You can see where the shots dispersed, and it was right by the hole. I'm just wondering if maybe he saw a little mouse or something and shot. Cause....I KNOW we got little mice too. I find the droppings from time to time. I sat outside for about 45min after my fiance "SHOT IT" and I didn't see anything.
Today, I get home from work, and my fiance tells me he's gonna drown whatever it is. Hmmmm.....maybe he's not as sure as he was last night that he got the little booger. SO...here we go....cramming the water hose under the barn and flooding it along with 2 of my chicken coops. YUCK! WELL....GUESS WHAT??? I didn't see anything swimming or drowning. And, he had taken the boards off from around the border of the bottom of the barn on 2 sides so the little devil could run out when the water started flooding. So we could see what in the dickens this predator is. NOTHING> maybe he's coming from somewhere else during the night, getting in under and the barn and crawling up under where 1 of my chicken coops are.........
So.....my lovable fiance has set a trap, shot his rifle and attempted to flood under the barn................................and I think we are still at square one. The trap went off in the barn twice. BUT the booger somehow managed to get out. (predator would step in through the chicken door, setting off the trigger and causing the chicken door to close behind it. Predator would be stuck in that part of the barn. And, it's sealed up. NO WAY he could have got back out unless he can swing the chicken door (its wooden). Evidently he can. Cause it happened twice. I was wondering if maybe it wasn't a mouse setting it off somehow.....cause they are really tiny and could squeeze through a crack or two.
My fiance has been hunting most of his life and he's um........56 I think.....ive even lost count. So, I know he's an excellent shot. BUT MAYBE...it was a mouse and the mouse just snatched its head in before he shot.
The story continues......................though my chicks are put up.................not gonna loose another one and that's FOR SURE!
If the killing is happening at night, it's NOT the sebrights. Chickens can't see at night, and once they're roosting, they're not going to move until morning for this reason. If the chicks are on the floor, it's definitely some kind of predator. If the chicks are just disappearing, I suspect they're being taken by something like rats or opossums. It could also be a snake. The ones that were injured may have been pecked by the sebrights (any chickens would do this; cannibalism is a trait of chickens and is not exclusive to sebrights. Always keep chickens separated until they're around the same size because they will get pecked by bigger, older chickens). The 4 month olds and the chicks that just disappeared were killed by something else. If there's even a tiny opening that provides access to the chicks, a rat or snake could easily get in there, so those would be my first guesses.